Summer Broadleaf Generation

When generating a new map in the forest biome, selecting either of the broadleaf options (clearing/forest) currently always generates a map with autumn leaves on half the trees. If I want to make a spring or summer themed map, I either have to manually cut out all the orange trees afterwards and repopulate the blank spots, or start with No Vegetation and add all the trees manually. An added option (either in the Vegetation box or as a new "Season" box next to it) should give the option to populate a new map with just green deciduous trees.